Apq
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CMake
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    <font size=5>CMake </font> is an extensible, open-source system that
    manages the build process in an operating system and compiler independent
    manner. Unlike many cross-platform systems, CMake is designed to be used
    in conjunction with the native build environment. Simple configuration
    files placed in each source directory (called CMakeLists.txt files) are
    used to generate standard build files (e.g., makefiles on Unix and
    projects/workspaces in Windows MSVC) which are used in the usual
    way. CMake can compile source code, create libraries, generate wrappers,
    and build executables in arbitrary combinations. CMake supports in-place
    and out-of-place builds, and can therefore support multiple builds from a
    single source tree. CMake also supports static and dynamic library
    builds.  Another nice feature of CMake is that it generates a cache file
    that is designed to be used with a graphical editor. For example, when
    CMake runs, it locates include files, libraries, and executable, and may
    encounter optional build directives. This information is gathered into
    the cache, which may be changed by the user prior to the generation of
    the native build files. (The following figure is the CMake cache GUI in
    the Windows MSVC environment.)
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    <img src="/CMake/Art/CMakeGUI.jpg" width=400 height=276 
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    <P>

    CMake is designed to support complex directory hierarchies and
    applications dependent on several libraries. For example, CMake supports
    projects consisting of multiple toolkits (i.e., libraries), where each
    toolkit might contain several directories, and the application depends on
    the toolkits plus additional code. CMake can also handle situations where
    executables must be built in order to generate code that is then compiled
    and linked into a final application. Because CMake is open source, and has
    a simple, extensible design, CMake can be extended as necessary to support
    new features.
    <P>

    Using CMake is simple. The build process is controlled by creating one or
    more CMakeLists.txt files in each directory (including subdirectories)
    that make up a project. Each CMakeLists.txt consists of one or more
    commands. Each command has the form COMMAND (args...) where COMMAND is
    the name of the command, and args is a white-space separated list of
    arguments. CMake provides many pre-defined commands, but if you need to,
    you can add your own commands. In addition, the advanced user can add
    other makefile generators for a particular compiler/OS combination.
    (While Unix and MSVC++ is supported currently, other developers are
    adding other compiler/OS support.) You may wish to study the
    <a href="/CMake/HTML/Examples.html">examples</a> page to see more
    details.

    <h3>A Summary Of Features</h3>
    CMake has several powerful features. These include:
    <ul>
      <li>Supports complex, large build environments. CMake has been
          proven in several large projects.
      <li>Generates native build files (e.g., makefiles on Unix;
          workspaces/projects on MS Visual C++). Therefore standard
          tools can be used on any platform/compiler configuration.
      <li>Has powerful commands include the ability to locate
          include files, libraries, executables; include external
          CMake files that encapsulate standard functionality;
          interfaces to testing systems; supports recursive
          directory traversal with variable inheritance; can run
          external programs; supports conditional builds; supports
          regular expression expansion; and so on.
      <li>Supports in-place and out-of-place builds. Multiple
          compilation trees are possible from a single source tree.
      <li>Can be easily extended to add new features.
      <li>CMake is open source.
      <li>CMake operates with a cache designed to be interfaced with
          a graphical editor. The cache provides optional interaction
          to conditionally control the build process.
    </ul>

    <h3>The Origins of CMake</h3> CMake was created in response to the need
    for a powerful, cross-platform build environment for the Insight
    Segmentation and Registration Toolkit (ITK) funded by NLM as part of the
    Visible Human Project. It was influenced by an earlier system called
    <b>pcmaker</b> created by Ken Martin and other developers to support the
    <a href="http://public.kitware.com/vtk.html">Visualization Toolkit
    (VTK)</a> open source 3D graphics and visualization system. To create
    CMake, Bill Hoffman at Kitware incorporated some key ideas from pcmaker,
    and  added many more of his own, with the thought to adopt some of the 
    functionality of the Unix
    <b>configure</b> tool. The initial CMake implementation was mid-2000,
    with acclerated development occuring in early 2001. Many improvements
    were due to the influences of other developers incorporating CMake into
    their own systems. For example, the 
    <a href="http://www.robots.ox.ac.uk/~vxl/">VXL</a> software community
    adopted CMake as their build environment, contributing many essential
    features. Brad King added several features in order to support the CABLE
    automated wrapping environment and 
    <a href="http://public.kitware.com/GCC_XML">GCC-XML</a>, and 
    GE Corporate R&D required support of their testing infrastructure 
    (the <a href="http://public.kitware.com/Insight/Testing/HTML/TestingResults/Dashboard/MostRecentResults-Nightly/Dashboard.html">quality dashboard</a>). 
    Other features were added to support the transition of VTK's
    build environment to CMake, and to support ParaView, a parallel
    visualization system to support the 
    <a href="http://www.acl.lanl.gov/">Advanced Computing Lab</a> at Los Alamos
    National Laboratory.

    <h3>How Do I Learn CMake?</h3> CMake is a young and rapidly growing
    system. It has already seen extensive use in very large software systems
    such as VTK, VXL, and ITK, and is therefore, quite
    stable. Unfortuneately, the pace of development has outstripped the pace
    of documentation. As a result, the best way to learn about CMake is to
    study existing CMake installations, and to rely on the CMake mailing
    list. There is some existing documentation, but until later in 2001 the
    documentation should be treated with caution. Please go to the
    <a href="/CMake/HTML/Documentation.html">documentation</a> for more
    information. Also, see the <a href="/CMake/HTML/Examples.html">example</a>
    found here.
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